Physics 3: Vibrations and Waves

Proof required

Link the public repo with the odd-numbered problems of chapter 15 and the 8.03SC Part I problem sets written up (a typeset PDF, LaTeX source or notebook), and show the self-check: which answers matched and how you fixed the ones that did not.

What gets checked

• The equation of motion is set up before it is solved.
• Damped and driven cases state the quality factor.
• Answers are checked against the key, and misses are reworked.

Common mistakes

• Answers copied from the key with no working.
• Wrong units or missing signs.

Powstik Guide

A public write-up of the odd-numbered problems of chapter 15 and the 8.03SC Part I problem sets, with the self-check shown.

Steps

1. Study the linked course and chapters.
2. Solve the problems on your own first.
3. Check them against the self-check and rework the misses.
4. Typeset the write-up (LaTeX or a notebook) in a public repo.
5. Ask someone who knows physics to check it.

README
Physics 3: Vibrations and Waves, unit 1: Oscillators, damping and resonance
Problems:
Self-check result (matched / reworked):
What I got wrong first and why:

What gets sent back

• No working shown.
• The self-check result is missing.

Resources

What a verifier looks for

• The equation of motion is set up before it is solved.
• Damped and driven cases state the quality factor.
• Answers are checked against the key, and misses are reworked.
• Is the physics right, not just the final number?

You'll sign in first, then come straight back here.

Proof required

Link the public repo with the odd-numbered problems of chapters 16–17 written up (a typeset PDF, LaTeX source or notebook), and show the self-check: which answers matched and how you fixed the ones that did not.

What gets checked

• Boundary conditions fix each set of normal modes.
• Fourier sums are checked against a plotted example.
• Answers are checked against the key, and misses are reworked.

Common mistakes

• Answers copied from the key with no working.
• Wrong units or missing signs.

Powstik Guide

A public write-up of the odd-numbered problems of chapters 16–17, with the self-check shown.

Steps

1. Study the linked course and chapters.
2. Solve the problems on your own first.
3. Check them against the self-check and rework the misses.
4. Typeset the write-up (LaTeX or a notebook) in a public repo.
5. Ask someone who knows physics to check it.

README
Physics 3: Vibrations and Waves, unit 2: Waves, sound and normal modes
Problems:
Self-check result (matched / reworked):
What I got wrong first and why:

What gets sent back

• No working shown.
• The self-check result is missing.

Resources

What a verifier looks for

• Boundary conditions fix each set of normal modes.
• Fourier sums are checked against a plotted example.
• Answers are checked against the key, and misses are reworked.
• Is the physics right, not just the final number?

You'll sign in first, then come straight back here.

Proof required

Link the public repo with the Part II problem sets, then a practice exam done timed written up (a typeset PDF, LaTeX source or notebook), and show the self-check: which answers matched and how you fixed the ones that did not.

What gets checked

• Wave equations are derived, not quoted.
• Energy flow uses the Poynting vector correctly.
• The practice exam is marked against its solutions, with the score.

Common mistakes

• Answers copied from the key with no working.
• Wrong units or missing signs.

Powstik Guide

A public write-up of the Part II problem sets, then a practice exam done timed, with the self-check shown.

Steps

1. Study the linked course and chapters.
2. Solve the problems on your own first.
3. Check them against the self-check and rework the misses.
4. Typeset the write-up (LaTeX or a notebook) in a public repo.
5. Ask someone who knows physics to check it.

README
Physics 3: Vibrations and Waves, unit 3: Electromagnetic waves
Problems:
Self-check result (matched / reworked):
What I got wrong first and why:

What gets sent back

• No working shown.
• The self-check result is missing.

Resources

What a verifier looks for

• Wave equations are derived, not quoted.
• Energy flow uses the Poynting vector correctly.
• The practice exam is marked against its solutions, with the score.
• Is the physics right, not just the final number?

You'll sign in first, then come straight back here.

Proof required

Link the public repo with the method, raw measurements, a photo of the set-up (and the laser's class label, if one is used), the analysis and the result, the result with its uncertainty, and a README that says what you did and what limits the result.

What gets checked

• The speed of sound and its uncertainty come from the fit, using the app's frequency step and the length measurement.
• The end correction is included, and the result is compared with 331 + 0.6 × T m/s at the measured room temperature T in °C.
• The set-up is safe: no mains power, no laser above class 2, reflections kept away from eyes, no radioactive material, no harmful heat or pressure.

Common mistakes

• A result with no uncertainty.
• Code or data that cannot be rerun from the repo.

Powstik Guide

A measurement of the speed of sound from the resonances of a tube (a cardboard tube or a plastic pipe), using a free phone tone generator or spectrum app, in a public repo.

Steps

1. Write down what you expect before you start.
2. Find at least three resonant frequencies, measure the tube's length and radius, add 0.6 × radius for each open end, and fit frequency against mode number (a tube closed at one end has only odd modes).
3. Work out the uncertainty from your own data.
4. Compare with the accepted value and explain any gap.
5. Write the README and ask someone who knows physics to check it.

README
Physics 3: Vibrations and Waves — Measure the speed of sound in a tube
What I expected:
Method:
Result (value ± uncertainty):
Accepted value and comparison:
What limits the result:

What gets sent back

• No uncertainty, or one that is guessed.
• An unsafe set-up.

Resources

What a verifier looks for

• The speed of sound and its uncertainty come from the fit, using the app's frequency step and the length measurement.
• The end correction is included, and the result is compared with 331 + 0.6 × T m/s at the measured room temperature T in °C.
• The set-up is safe: no mains power, no laser above class 2, reflections kept away from eyes, no radioactive material, no harmful heat or pressure.
• The uncertainty is worked out from the data or runs (spread of repeats, instrument limits, fit errors or a range of inputs), not guessed, and it is shown on the result.
• Is the physics right, and could someone rerun it from the repo?

You'll sign in first, then come straight back here.